Recently, liquid crystal devices have been widely used in display units of electronic apparatuses such as portable computers, mobile telephones, video cameras, and so on. In general, these liquid crystal devices are formed such that a pair of substrates, each having electrodes formed thereon are bonded by a ring of sealing material such that the electrodes are oriented parallel to each other, and the liquid crystal is encapsulated in the region enclosed by the pair of substrates and the sealing material. In these liquid crystal devices, images such as text, numerals, graphics, and so on are displayed by controlling the orientation of the liquid crystal encapsulated between the pair of substrates at each pixel.
Among these liquid crystal devices, there are simple matrix liquid crystal devices which do not use active elements and active matrix liquid crystal devices which use active elements. TFD (Thin Film Diode) elements, which are two-terminal active devices, and TFT (Thin Film Transistor) elements, which are three-terminal active devices, are known as such active elements.
Conventionally, as shown in FIG. 15, for example, simple matrix liquid crystal devices which are formed such that a pair of substrates 151a and 151b made of glass or the like are bonded by a ring of sealing material 152 made of an epoxy resin or the like are known. The first one of the substrates, substrate 151a, has a substrate projecting part 153a which projects further outside than the other substrate 151b, and the other substrate 151b has a substrate projecting part 153b which projects further outside than the first substrate 151a. 
A plurality of strip-shaped electrodes 154a are formed of, for example, ITO (Indium Tin Oxide) on the inside surface of the first substrate 151a, and a plurality of strip-shaped electrodes 154b are formed of, for example, ITO on the inside surface of the other substrate 151b. When the pair of substrates 151a and 151b are bonded, these electrodes 154a and 154b orthogonally intersect each other, and each intersection point forms one pixel.
The electrodes 154a formed on the first substrate 151a have wiring lines 156a which extend onto the substrate projecting part 153a by passing through the sealing material 152, and, at the same time, also have dummy patterns 157a which pass through the sealing material 152 at the side opposite to the substrate projecting part 153a. Electrodes 154b are also formed on the other substrate 151b in the same way. Liquid crystal driving ICs (Integrated Circuits; not shown in the drawing) are mounted on the substrate projecting parts 153a and 153b, and the wiring lines 156a of the electrodes 154a and the wiring lines 156b of the electrodes 154b are connected to the terminals of these liquid crystal driving ICs.
Liquid crystal is encapsulated in the region enclosed by the substrate 151a, the substrate 151b, and the sealing material 152. This region is called a liquid crystal encapsulating region R. By controlling the voltage applied to this liquid crystal at each pixel, defined by the intersection points of the electrodes 154a and the electrodes 154b, light which is incident from outside the substrate 151a or the substrate 151b and transmitted therethrough is modulated at each pixel, and, accordingly, an image such as text is displayed on the outer side of the substrate 151a or the substrate 151b. 
In the conventional liquid crystal device, if a structure in which the wiring lines 156a pass underneath the sealing material 152 at the substrate projecting part 153a side while, on the other hand, the electrodes 154a do not pass underneath the sealing material 152 at the side opposite the substrate projecting part 153a is used, since the cell thickness at the end of the liquid crystal panel at the side opposite the substrate projecting part 153a becomes smaller by an amount equal to the part having no electrodes 154a, the cell thickness between the substrate projecting part 153a side and the side opposite thereto becomes nonuniform. When such a nonuniformity in the cell thickness occurs, the threshold voltage Vth at which the liquid crystal is turned ON/OFF becomes nonuniform between the substrate projecting part 153a side and the side opposite thereto, and, for that reason, a problem occurs in that the display quality of the liquid crystal device is reduced.
In the conventional liquid crystal device, the reason why the dummy patterns 157a, which pass underneath the sealing material 152 at part of the electrodes 154 positioned at the side opposite to the substrate projecting part 153a, are formed is that they prevent the height of the liquid crystal encapsulating region R, that is to say, the cell gap height, or in other words, the cell thickness, between the substrate projecting part 153a side and the side opposite thereto from becoming nonuniform.
However, in the conventional liquid crystal device in which the dummy patterns 157a are provided as described above, the configuration is such that the dummy patterns 157a are formed by extending the electrodes 154a while maintaining their width, and that is why the width of the dummy patterns 157a is the same as the width of the electrodes 154a. Accordingly, the ratio of the area underneath the sealing material 152 occupied by the wiring lines 156a, which pass through the sealing material 152 at the substrate projecting part 153a side, is different from the ratio of the area underneath the sealing material 152 occupied by the dummy patterns 157a, which pass through the sealing material 152 at the side opposite the substrate projecting part 153a. In particular, the ratio of the area occupied by the dummy patterns 157a at the side opposite the substrate projecting part 153a is larger.
Generally, in order to maintain the cell thickness at the sealing material, spherical or cylindrical spacers 158 are dispersed therein. However, when the ratio of the area occupied by the wiring lines 156a and the ratio of the area occupied by the dummy patterns 157a differ from each other, the number of spacers 158 sitting on top of the wiring lines 156a is not the same as the number of spacers 158 sitting on top of the dummy patterns 157a. In particular, the number at the substrate projecting part 153a side, where the area occupation ratio is small, is smaller than the number at the dummy pattern 157a side, where the area occupation ratio is large.
There is a tendency for the spacers 158 in the sealing material 152 to be compressed and crushed by the pair of substrates 151a and 151b; however, compared to the large number of spacers sitting on the dummy pattern 157a, where the area occupation ratio is large, the small number of spacers 158 sitting on the wiring lines 156a, where the area occupation ratio is small, are crushed to a greater extent. Accordingly, when the extent to which the spacers 158 are crushed at the two sides of the liquid crystal panel is different, a nonuniformity in the cell thickness occurs between one side of the liquid crystal panel and the other side, even when the dummy patterns 157a are formed. As a result, there is a problem in that the display quality deteriorates due to nonuniformity in the threshold voltage Vth.
Among liquid crystal devices, those having a structure in which liquid crystal driving ICs are directly mounted on the substrate projecting parts by the so-called COG (Chip On Glass) method are known. In these COG-method liquid crystal devices, since the plurality of electrodes which form the liquid crystal display region must be made to converge towards the terminals of the liquid crystal driving ICs on the substrate projecting parts, the wiring lines 156a of the electrodes 154a shown in FIG. 15 must be formed more finely, that is to say, with a narrower pattern width.
As a result, when the pattern width at one side becomes narrower, the extent to which the above-described spacers 158 are crushed becomes even more pronounced. Moreover, since the electrical resistance correspondingly increases when the pattern width becomes narrower, in order to prevent this, it is necessary to reduce the electrical resistance by increasing the pattern height, that is to say, by increasing the film thickness of the electrode. Increasing the film thickness of the electrode in this way causes the cell thickness nonuniformity due to the different level of crushing of the spacers 158 in the sealing material to become more pronounced.
In addition, in recent years there has been an increasing demand for liquid crystal devices capable of high-definition display and color display. In order to achieve these types of displays, the electrodes 154a and 154b shown in FIG. 15 must be made even more finely and the number of these electrodes must be increased. Such a decrease in the electrode width means that the film thickness must be increased, as described above, and as a result, the difference in the level of crushing of the spacers 158 in the sealing material induces a large cell thickness nonuniformity.
Moreover, a conventional liquid crystal device which uses a simple-matrix-type liquid crystal panel 110 shown in FIG. 16 is known. In this liquid crystal panel 110, a first substrate 111a and a second substrate 111b, which are made from glass, plastic, or the like, are bonded by a sealing material 113. Here, the structure is such that spherical or cylindrical spacers which have a diameter on the order of 5 to 10 μm and which are made from, for example, resin are mixed in the sealing material 113 and the spacing between the substrates is controlled by the spacers when the first substrate 111a and the second substrate 111b are joined together during substrate bonding, thus allowing the spacing between the substrates to be precisely set to a fixed value.
In the liquid crystal panel 110, a plurality of strip-shaped first electrodes 112a are arranged in parallel to each other to extend in a predetermined direction on the surface of the first substrate 111a, that is to say, in the form of stripes. Also, on the surface of the second substrate 111b, a plurality strip-shaped second electrodes 112b are arranged in parallel to each other to extend in the direction orthogonal to the first electrodes 112a, that is to say, in the form of stripes. Then, a driving region Z is formed by horizontally and vertically arraying the regions where the first electrodes 112a and the second electrodes 112b, which are formed on the surfaces of the substrates 111a and 111b, respectively, intersect each other, that is to say, pixel regions, in the shape of a matrix.
The first substrate 111a has a substrate projecting part 114a which projects further towards the outside than the second substrate 111b. Also, the second substrate 111b has a substrate projecting part 114b which projects further towards the outside than the first substrate 111a. First wiring lines 116a which are electrically connected to the first electrodes 112a pass through the region where the sealing material 113 is formed and are led out onto the substrate projecting part 114a. Also, second wiring lines 116b which are electrically connected to the second electrodes 112b pass through the region where the sealing material 113 is formed and are led out onto the substrate projecting part 114b. 
Input terminals 117a and 117b are formed at the outer edges of the substrate projecting parts 114a and 114b, respectively. In addition, IC chips 118a and 118b, which are formed of semiconductor ICs, are mounted at the ends of the first wiring lines 116a and second wiring lines 116b and at the ends of the input terminals 117a and 117b. 
At the opposite side from the first wiring lines 116a, the first electrodes 112a have extended dummy patterns 119a which extend outside the driving region Z. Also, at the opposite side from the second wiring lines 116b, the second electrodes 112b have extended dummy patterns 119b which extend outside the driving region Z. The extended dummy patterns 119a are connected to the first electrodes 112a, and the extended dummy patterns 119b are connected to the second electrodes 112b. 
The extended dummy patterns 119a are formed such that they pass through a part 113a of the sealing material 113, and the extended dummy patterns 119b are formed such that they pass through a part 113b of the sealing material 113. The reason for forming such a structure is as follows. The first wiring lines 116a pass through a part 113c provided towards the substrate projecting part 114a side of the sealing material 113. In addition, the second wiring lines 116b pass through a part 113d provided towards the substrate projecting part 114b side of the sealing material 113. In this state, if the extended dummy patterns 119a do not pass through the part 113a provided at the side of the sealing material 113 opposite to the substrate projecting part 114a, and furthermore if the extended dummy patterns 119b do not pass through the part 113b provided at the side of the sealing material 113 opposite to the substrate projecting part 114b, the spacing between the substrates at the positions of the parts 113c and 113d will be larger than that at the parts 113a and 113b by an amount equal to the thickness of the first wiring lines 116a and second wiring lines 116b, respectively. The reason why the extended dummy patterns 119a and extended dummy patterns 119b are formed such that they pass through the part 113a and the part 113b of the sealing material 113, respectively, is to prevent such a nonuniformity in the substrate spacing.
Therefore, by providing a structure such that the extended dummy patterns 119a and 119b pass through the parts 113a and 113b, respectively, of the sealing material 113 in the manner described above, the nonuniformity in the substrate spacing in the driving region due to each of the parts 113a, 113b, 113c, and 113d of the sealing material 113 can be reduced. Such a nonuniformity in the substrate spacing causes display nonuniformity due to differences in the liquid crystal threshold voltage. The deterioration in display quality is particularly pronounced in STN (Super Twisted Nematic) type liquid crystal display devices which are sensitive to changes in the substrate spacing.
However, for the reasons given below, it is difficult to reduce the difference between the substrate spacing at the parts 113d and 113c of the sealing material 113 and the substrate spacing at the parts 113b and 113a of the sealing material 113 to a degree which makes it possible to provide sufficiently high image quality in the liquid crystal device.
For example, as shown in FIG. 17, in order to form a row of terminals for the IC chip 118b (see FIG. 16), the width of the second wiring lines 116b is set to be narrower than the width of the second electrodes 112b. In addition, the array spacing of the second wiring lines 116b, that is to say, the spacing at which they are formed, or in other words, the pitch, is also set to be narrower than the array spacing of the second electrodes 112b. Accordingly, the extended dummy patterns 119b are formed with a width and an array spacing which are substantially the same as the second electrodes 112b. Because of this, the area occupation ratio of the second wiring lines 116b with respect to the part 113d of the sealing material 113 (in other words, the ratio of area occupied by the portions of the second wiring lines 116b which pass through the sealing material with respect to the area of the part 113d) is smaller than the area occupation ratio of the extended dummy patterns 119b with respect to the part 113b of the sealing material 113 (in other words, the ratio of area occupied by the portion of the extended dummy patterns 119b which pass through the sealing material with respect to the area of the part 113b).
For that reason, the number of spacers sitting on the second wiring lines 116b at the part 113d is less than the number of spacers sitting on the extended dummy patterns 119b at the part 113b, and, as a result, the bonding pressure applied during substrate bonding is borne by the part 113d. When this happens, a difference in substrate spacing between the part 113d and at the part 113b remains due to the difference in the degree of crushing of the spacers. The situation is exactly the same for the first electrodes 112a in FIG. 16.
Recently, there have been many demands for liquid crystal devices having high-definition display and color display capabilities. In realizing these types of display, it is necessary to increase the number of first electrodes 112a and second electrodes 112b by making their width smaller, and in this case the width of the electrodes becomes smaller. Since the electrical resistance increases as a result of reducing the electrode width in this way, it is necessary to form the first electrodes 112a and the second electrodes 112b with a larger thickness in order to prevent such an increase in electrical resistance. In this case, the first wiring lines 116a and the extended dummy patterns 119a, which are formed at the same time as the first electrodes 112a, as well as the second wiring lines 116b and the extended dummy patterns 119b, which are formed at the same time as the second electrodes 112b, also become thicker. Therefore, since the difference in the controlled force applied to the spacers with respect to the substrate spacing both in the case where the spacers sit on the wiring lines and the dummy patterns and in the case where they do not, increases, the difference in the amount of crushing of the spacers becomes larger, and, as a result, the nonuniformity in substrate spacing also becomes larger.
Furthermore, in liquid crystal devices having high-definition display and color display capabilities, the number of connection terminals of the IC chips increases corresponding to increases in the number of pixels and the number of electrodes, and, likewise, there is also a tendency for the spacing between terminals, that is to say, the terminal pitch, to be reduced. Therefore, the ratio of the width and array spacing, that is to say, the pitch, between the first electrodes 112a and the first wiring lines 116a in the driving region Z, as well as the ratio of the width and the pitch between the second electrodes 112b and the second wiring lines 116b also have a tendency to increase. As a result, the nonuniformity in substrate spacing also increases.
In Japanese Utility Model Application Publication No. 4-087822, there is disclosed a technology wherein, in a liquid crystal display panel which has a pair of glass substrates bonded by a sealing material, when the electrode width is changed at the location of the sealing portion, indentations and projections are prevented from occurring on the substrate surface corresponding to the sealing portion by forming dummy electrode patterns at the sealing portion. However, the dummy electrode patterns disclosed in that document are provided at the location of the sealing portion, and, as a result, it is difficult to make the cell gap uniform over a wide area of the liquid crystal panel.
In Japanese Patent Application Publication No. 5-203966, there is disclosed a technology wherein, in a color liquid crystal electrooptical device which is formed by bonding a color filter substrate and a transparent substrate via a sealing portion, by providing separate transparent electrode patterns as driving electrode patterns at the sealing portion, the cell gap is made more uniform than in the case in which portions where there are transparent electrodes and portions where there are no transparent electrodes both exist at the position where the sealing portion is provided. However, with the technology disclosed in that document, the electrode patterns for ensuring uniformity of the cell gap are provided linearly along the sealing material rather than being provided connected to the driving electrode patterns which pass through the sealing portion. As a result, it is difficult to make the cell gap uniform over a wide area of the liquid crystal panel.